[INFO] fetching crate js-object 0.2.0...
[INFO] testing js-object-0.2.0 against beta-2021-09-08 for beta-1.56-1
[INFO] extracting crate js-object 0.2.0 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate js-object 0.2.0 on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate js-object 0.2.0
[INFO] finished tweaking crates.io crate js-object 0.2.0
[INFO] tweaked toml for crates.io crate js-object 0.2.0 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded js-intern-core v0.3.1
[INFO] [stderr]   Downloaded js-intern-proc-macro v0.3.1
[INFO] [stderr]   Downloaded js-intern v0.3.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 56e50ed6edcb9c77362641c5983f269ec258a8ad7f99f903bd266367eccf60c5
[INFO] running `Command { std: "docker" "start" "-a" "56e50ed6edcb9c77362641c5983f269ec258a8ad7f99f903bd266367eccf60c5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "56e50ed6edcb9c77362641c5983f269ec258a8ad7f99f903bd266367eccf60c5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "56e50ed6edcb9c77362641c5983f269ec258a8ad7f99f903bd266367eccf60c5", kill_on_drop: false }`
[INFO] [stdout] 56e50ed6edcb9c77362641c5983f269ec258a8ad7f99f903bd266367eccf60c5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 42c4d61b6c0f55fdd8e1bcf6c06fb08f0523b9855c15bd44c0d403be5d7ca0ad
[INFO] running `Command { std: "docker" "start" "-a" "42c4d61b6c0f55fdd8e1bcf6c06fb08f0523b9855c15bd44c0d403be5d7ca0ad", kill_on_drop: false }`
[INFO] [stderr]    Compiling js-intern-core v0.3.1
[INFO] [stderr]    Compiling js-intern-proc-macro v0.3.1
[INFO] [stderr]    Compiling js-intern v0.3.1
[INFO] [stderr]    Compiling js-object v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization, proc_macro_hygiene)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization, proc_macro_hygiene)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `js-object` due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "42c4d61b6c0f55fdd8e1bcf6c06fb08f0523b9855c15bd44c0d403be5d7ca0ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "42c4d61b6c0f55fdd8e1bcf6c06fb08f0523b9855c15bd44c0d403be5d7ca0ad", kill_on_drop: false }`
[INFO] [stdout] 42c4d61b6c0f55fdd8e1bcf6c06fb08f0523b9855c15bd44c0d403be5d7ca0ad